Resumen

MARQUEZ-SANCHEZ, Fidel. Inbreeding in a maize synthetic of selfed-sib families (S₁ lines). Rev. fitotec. mex [online]. 2013, vol.36, n.3, pp.259-261. ISSN 0187-7380.

Synthetics are genetically improved populations for farmers that cannot buy hybrid seed. In this paper, inbreeding is calculated for a maize synthetic (Zea mays L.) created with selfed-sib families (AH) or S₁ lines. The synthetic is obtained from the first generation by open pollination of a balanced composite made with the families. Inbreeding in the first generation is calculated through an equation that includes several generations: F(AH)₁ = (1/4nm) [(2m + 1) + 4 m(n - 1)F₁ + 2(m - 1)F₀ + F₁], where n is the number of families, m the number of plants per family, and F is the inbreeding coefficient which sub-indexes are the generation numbers. After elimination of the terms with zero inbreeding in the recurrent equation , inbreeding in an F₁ synthetic with 10 families and 10 plants per family is equal to 0.0526. The number of families affects more the synthetic inbreeding than the number of plants per family.

Palabras llave : Zea mays; inbreeding; selfed-sib families; synthetic variety.